Fuel supply system and fuel delivery method

Abstract

Invention patent: “FUEL SUPPLY SYSTEM AND FUEL SUPPLY METHOD”. Applicable to internal combustion engines that are powered by at least one fuel which makes it possible to achieve the atomization state of the fuel at lower temperatures, resulting in lower electricity and fuel consumption.

Description

[0001] The present invention relates to a fuel supply system equipped with a fuel heating device and the corresponding fuel supply method, which includes the use of heated fuel, preferably used in vehicle engines, and which supplies fuel with better atomization to the injectors. STATE OF THE ART

[0002] In recent years, the amount of pollutants (HC, CO, CO2 and particulate matter, among others), emitted mainly by car engines, has been a major problem for large cities. Therefore, new technologies have been developed to help reduce pollutant emissions from combustion engines.

[0003] To reduce greenhouse gas emissions from automobiles and decrease dependence on fossil fuels, several alternatives to replacing the internal combustion engine are available. However, the best solution to this dilemma must take into account the country's geographical and socioeconomic characteristics, its energy matrix, its emissions legislation, and the environmental impact of the fuel's carbon emissions throughout its entire life cycle.

[0004] Brazil enjoys a strong reputation for its fleet of bi-fuel vehicles, its long-standing experience in using ethanol fuel, and its distribution network. This sets it apart from other global markets and justifies a unique approach to reducing emissions such as aldehydes.

[0005] However, there are some limitations to the use of bi-fuel engines (commonly known as "flex" engines). To meet the demand for using two fuels in a single tank, the sizing of a flex engine tends to be medium-sized, as the sizing of single-fuel engines varies depending on whether it's ethanol or gasoline. This is because the vast majority of bi-fuel engines typically have a single geometric compression ratio (which is the ratio between the intake volume and the combustion chamber volume).

[0006] During its stroke, the piston reaches a higher and a lower point in its displacement, which is referred to as top dead center (TDC) and bottom dead center (BDC), respectively.

[0007] Normally, the operation of a passenger car's engine has four strokes: • Admission • Compression • Burning • Exhaustion

[0008] The effect of the compression ratio becomes apparent in the second stroke – the intake valves close after the injection of the air-fuel mixture, compressing it so that the combustion process can begin. This gives us the geometric compression ratio of the engine: the ratio between the volume of the combustion chamber at the piston's bottom dead center (BDC) (larger volume) and its top dead center (TDC) (smaller volume).

[0009] Petrol engines often use lower compression ratios (typically between 8:1 and 12:1), while ethanol-powered engines with higher ratios (12:1 or even 14:1) perform better.

[0010] Before the fuel reaches the combustion chamber, it travels from the vehicle's tank. This fuel is moved by a fuel pump and flows through pipes that transport the fuel – first through a hose and later through a more rigid and branched channel, known as the gallery. The branches cause the fuel to be injected into the respective cylinders, and the fuel injectors are located at the outlets of these branches.

[0011] Furthermore, fuel splashing onto the piston surface or intake port walls can contribute to an increase in emitted particles. Additionally, fuel condensation in cold engine zones can lead to incomplete combustion, producing hydrocarbons and carbon monoxide (HC and CO).

[0012] When it comes to engines that use the Otto cycle (engines traditionally used in automobiles), both those using port fuel injection (PFI) and those using direct injection (DI) emit particles exceeding the permissible limits. Therefore, the use of a particulate filter for gasoline engines (its acronym is GPF, derived from the English "Gasoline Particulate Filter") has been recommended to comply with the new legislation on particulate emissions that has come into force.

[0013] However, even with the use of GPF, engines can still produce particles that exceed the limits set by official health authorities, as pollutant emissions also depend on the behavior of drivers in terms of their driving style and the proper maintenance of the vehicles.

[0014] However, one of the most effective techniques to achieve a more correct combustion of the fuel is to direct it into the previously heated combustion chamber.

[0015] The fuel is heated by means of heaters that are placed as close as possible to each injector (most efficient method), which can be integrated into it or mounted directly in front of the injector to supply the injector with fuel flowing through the properly heated gallery.

[0016] The heating must be the same for all injectors so that all injectors receive the fuel at the same temperature, ensuring homogeneous combustion in all cylinders, regardless of the configuration: from injection systems that use one injector to supply each cylinder individually, or from multiple injectors per cylinder.

[0017] Theory and practice show that higher temperatures than currently used would result in additional emission reductions, while simultaneously requiring higher fuel supply pressure. If this higher pressure is applied throughout the vehicle's operating time, it leads to increased electrical power consumption and thus higher fuel consumption. This increased electrical power consumption also results in greater wear and tear on some components.

[0018] Furthermore, heating systems have physical, electrical, and thermal limitations that prevent the injected fuel from being fully heated. In extreme situations with immense thermal amplitudes (differences between the initial fuel temperature before and after injection), the heater may not be able to supply all the heat energy required for the fuel to reach the desired target temperature (e.g., when the ambient temperature is very low).

[0019] In this sense, a solution is sought for a system that provides fuel with a specific pressure that only acts during cold start and engine warm-up, which can enable better atomization of the fuel in all injectors.

[0020] In this sense, patent document US2003209232 defines the use of two different pressures to extend the limits of possible flow variations for the same injector, but without taking into account the atomization effects for liquids with a higher flash point.

[0021] Therefore, the present invention proposes to solve the prior art problem in a significantly more efficient manner by providing more efficient, balanced heating and consequently better atomization of the fuel in all injectors. GOALS OF THE INVENTION

[0022] The objective of the present invention is to provide a fuel supply system applicable to internal combustion engines powered by at least one fuel in an efficient manner, thereby making it possible to achieve the atomization state of the fuel at lower temperatures, consequently resulting in lower power consumption and lower fuel consumption.

[0023] A further objective of the present invention is to provide a fuel supply method applicable to internal combustion engines powered by at least one fuel applicable to the system in an efficient manner, thereby making it possible to achieve the atomization state of the fuel at lower temperatures, consequently resulting in lower power consumption and lower fuel consumption. BRIEF DESCRIPTION OF THE INVENTION

[0024] In order to solve the presented technical problem and overcome the disadvantages of the prior art, one objective of the present invention is to provide a fuel supply system applicable to internal combustion engines powered by at least one fuel, with • at least one device for fuel distribution and injection; • at least one fuel-powered heating device; • at least one first fuel line with a first line end connected to a fuel supply unit and a second line end connected to at least one fuel distribution and injection device; • at least one second line for fuel return; • at least one reservoir; • at least one pressure-generating element; • a first pressure regulating element that is mechanically and fluidically connected to the pressure-generating element; so that it includes the following • a flow control element assigned to the second fuel return line; • a third line for fuel return, which is connected to the second line; • a second pressure regulating element that is mechanically and fluidically connected to the third line.

[0025] A further objective of the present invention is to provide a method for fuel supply that is applicable to the fuel supply system in question and comprises the following steps. • Determination of the presence and quantity of at least one biofuel in the storage site; • Comparison with a reference value relating to the quantity of at least one biofuel present in the previously defined storage tank and required to switch on at least one fuel heating device; • Performing an action. BRIEF DESCRIPTION OF THE DRAWINGS Fig. - Overview of the fuel supply system. Fig. - Example of the effect of pressure increase on fuel atomization. DETAILED DESCRIPTION OF THE DRAWINGS

[0026] The fuel heater and heating management system are responsible for heating the fuel injected into the engine to a predetermined temperature. Heating the fuel aims to improve the atomization of the injected fuel spray by reducing its droplet size. This results in a better preparation of the air-fuel mixture, leading to a more homogeneous mixture. Consequently, the amount of fuel injected is reduced, thus lowering the amount of emitted gases and particles.

[0027] The heating system operates from the moment the engine is started. The system's management aims to maintain the injected fuel temperature at the target temperature at all times. To achieve this, the system determines the amount of energy required to supply the fuel based on the fuel's entry temperature, the fuel flow rate, and the type of fuel.

[0028] If the fuel temperature management system is able to accurately deliver the fuel at the highest temperature, then the measured or calculated temperature of the fuel leaving the combustion chamber is indeed the temperature for which the energy was allocated and supplied, thus preventing energy waste. Furthermore, the fuel atomization is increased, which improves combustion.

[0029] In this way, the pressure of the injected fuel directly influences the heating, atomization and delivery of the heated fuel to the cylinder. Fig. illustrates the improvement in atomization with increasing fuel pressure and temperature.

[0030] In this respect, it should be ensured that the heated fuel is injected into all cylinders with optimal atomization.

[0031] To achieve the objectives, the present invention discloses, as described in Fig. The image shows a fuel supply system applicable to internal combustion engines powered by at least one fuel, equipped with • at least one device for fuel distribution and injection 6; • at least one fuel-powered heating device; • at least one first fuel line 1 with a first end 11 connected to a fuel supply unit 5 and a second end 12 connected to at least one fuel distribution and injection device 6; • at least one second line 2 for fuel return; • at least one reservoir 72; • at least one fuel supply set 7, equipped with at least one pressure generating element 71 and a first pressure regulating element, which is mechanically and fluidically connected to the pressure generating element 71; • to include a flow control element 4 which is connected to the second line 2 for fuel return; • a third line 3 for fuel return, which is connected to the second line 2; • a second pressure regulating element 5, which is mechanically and fluidically connected to the third line 3.

[0032] Internal combustion engines that are operated with at least one fuel are preferably understood to be bi-fuel or flex engines that are operated with ethanol and gasoline, but are not limited to bi-fuels and not only to these two fuels.

[0033] A fuel heating device is any device that can heat fuel and that can be positioned at any point between the tank and the injector. Preferably, it is a device with the dedicated function of heating the fuel only before it is injected into the combustion chamber.

[0034] A first line 1 is understood to be the main line for the transport and flow of the fuel, which extends from the container 72 (tank) to the device for the distribution and injection of the fuel 6 (gallery and injectors).

[0035] The second line 2 is understood as a return line for the excess injectable fuel to tank 7.

[0036] A pressure regulating element is a component that controls the volume and serves to maintain a consistent fuel pressure. Excess fuel that may occur during engine operation is returned to the tank via a valve, known as the return line.

[0037] A fuel supply set 7 is a set consisting of a pressure generating element 71 (pump) and at least one pressure regulator. It typically includes a level sensor, a housing, a cover, and hydraulic and electrical connections.

[0038] The present invention describes a fuel supply system such that the flow control element 4 comprises a valve.

[0039] The present invention describes a fuel supply system, wherein the third line 3 comprises a first end of the third line 31, which is mechanically and fluidically connected to the second line 2 in a region upstream of the flow control element 4, and a second end of the third line 32, which is mechanically and fluidically connected to the second line 2 in a region downstream of the flow control element 4.

[0040] The present invention describes a fuel supply system, wherein the first pressure regulating element comprises a low-pressure regulating element.

[0041] The present invention discloses a fuel supply system wherein the second pressure regulating element 5 comprises a high-pressure regulating element.

[0042] The present invention discloses a fuel supply system applicable to vehicles that are powered by at least two fuels.

[0043] The present invention describes a fuel supply system applicable to vehicles powered by at least one biofuel.

[0044] The present invention describes a fuel supply system wherein the biofuel comprises any ethanol mixture. Preferably, the biofuel is E100 ethanol.

[0045] Furthermore, the present invention describes a fuel supply method applicable to the fuel supply system that is the subject of the present invention and the steps • Detect at least one fuel condition; • Performing an action includes.

[0046] Detecting at least one fuel condition means recognizing the type of each fuel and the mixture or ratio between them present in the tank when more than one fuel is present.

[0047] The present invention describes a method for transporting fuel, such that the step of recognizing at least one fuel state comprises the steps • Determining the presence and quantity of at least one biofuel at storage site 72; • Compare with a reference value based on the quantity of at least one biofuel present in the previously defined container 72, which is required to switch on at least one fuel heating device; includes.

[0048] The present invention also discloses a method for transporting fuel, wherein the step of performing an action comprises performing an action between positioning the flow control element 4 in the open position and positioning the flow control element 4 in the closed position.

[0049] The opening and closing of the flow control element 4 can be carried out by means of a timer or another signal relating to the temperature of the injected fuel or another vehicle parameter.

[0050] The control of the heaters, i.e., the determination of the amount of energy required for the fuel to reach a target temperature, must be carried out by a parameter processing control unit of the vehicle, which is preferably responsible for the intelligence of the engine as a whole. This control unit can include either the ECU (Electronic Control Unit) already present in the vehicle – responsible for the electronic control of the entire engine operation – or a dedicated unit exclusively for the HCU (Heating Control Unit) fuel heating system.

[0051] It should therefore be noted that, as described above, the present invention fully achieves the objective of providing a fuel supply system applicable to internal combustion engines powered by at least one fuel in an efficient manner, thereby making it possible to achieve the atomization state of the fuel at lower temperatures, consequently resulting in lower power consumption and lower fuel consumption.

[0052] Similarly, the present invention also fulfills the objective of providing a fuel supply method applicable to internal combustion engines powered by at least one fuel applicable to the system in an efficient manner, thereby making it possible to achieve the atomization state of the fuel at lower temperatures, consequently resulting in lower power consumption and lower fuel consumption.

[0053] Therefore, the present invention also fulfills the role of increasing the power extracted from the engine, which is associated with lower fuel consumption and a resulting reduction in environmentally harmful gases from the engines. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] US 2003209232

[0020]

Claims

[1] A fuel supply system for internal combustion engines powered by at least one fuel, equipped with • at least one device for fuel distribution and injection (6); • at least one fuel-powered heating device; • at least one first fuel line (1) with a first line end (11) connected to a fuel supply arrangement (7) and a second line end (12) connected to at least one fuel distribution and injection device (6); • at least one second line (2) for fuel return; • at least one reservoir (72); • at least one pressure-generating element (71); • a first pressure regulating element which is mechanically and fluidically connected to the pressure-generating element (71); characterized in that it • a flow control element (4) connected to the second line (2) for fuel return; • a third line (3) for fuel return, which is connected to the second line (2); • a second pressure control element (5) which is mechanically and fluidically connected to the third line (3), wherein the third line (3) comprises a first end of a third line (31) which is mechanically and fluidically connected to the second line (2) in a region upstream of the flow control element (4), and a second end of a third line (32) which is mechanically and fluidly connected to the second line (2) in a region downstream of the flow control element (4). [2] Fuel supply system according to claim 1, characterized by , that the flow control element (4) includes a valve. [3] Fuel supply system according to claim 1, characterized bythat the first pressure regulating element includes a low-pressure regulating element. [4] Fuel supply system according to claim 1, characterized by , that the second pressure regulating element (5) comprises a high-pressure regulating element. [5] Fuel supply system according to claim 1, characterized by that it is applicable to vehicles powered by at least two fuels. [6] Fuel supply system according to claim 1, characterized by that it is applicable to vehicles powered by at least one biofuel. [7] Fuel supply system according to claim 6, characterized by that the biofuel comprises any ethanol mixture. [8] Fuel supply method applicable to a fuel supply system as defined by claims 1 to 7, characterized by that it includes the following steps: • Detect at least one fuel condition; • Performing an action, wherein the step of detecting at least one fuel state includes the steps • Determining the presence and quantity of at least one biofuel in the reservoir (72); • Comparing with a reference value relating to the quantity present in the previously defined tank (72) required for the connection of at least one fuel heating device; includes, and the step of performing an action includes performing an action between positioning the flow control element (4) in the open position and positioning the flow control element (4) in the closed position.

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